Accumulating conveyor

ABSTRACT

A series of live rollers have reduced diameter portions centrally thereof forming grooves receiving and guiding an endless drive member having one side in frictional contact therewith. The drive member thickness is less than the roller groove depth and spaced pads on the drive member project slightly above the article engaging surfaces of the rollers to engage the trailing edge of a stationary load and initiate forward movement thereof.

United States Patent 1191 Milazzo et al.

1451 Feb. 12, 1974 ACCUMULATING CONVEYOR Inventors: Carl J. Milazzo,Tonawanda; Frank J. I-Iohl, Snyder, both of N.Y.

I-Iohl Machine & Conveyor Co., Inc., Buffalo, NY. 1

Filed: Dec. 23, 1971 Appl. No.: 211,351

[73] Assignee:

us. c1. 198/127 R, 198/173 Int. Cl. B65g 13/02 Field of Search 198/127,173

References Cited UNITED STATES PATENTS 2,253,198 --"8/l941 Regan 198/127R 2,990,941 7/1961 Peras 198/173 3,650,376 3/1972 Burgis et al 198/160FOREIGN PATENTS OR APPLICATIONS 697,901 9/1953 Great Britain 198/127 RPrimary Examiner-Evon C. Blunk Assistant ExaminerJoseph E. ValenzaAttorney, Agent, or FirmChristel & Bean [57] ABSTRACT A series of liverollers have reduced diameter portions centrally thereof forming groovesreceiving and guiding an endless drive member having one side infrictional contact therewith. The drive member thickness is less thanthe roller groove depth and spaced pads on the drive member projectslightly above the article engaging surfaces of the rollers to engagethe trailing edge of a stationary load and initiate forward movementthereof.

7 Claims, 5 Drawing Figures PAIENIEUFEB I 2 I974 LE AWUHHHW w. 1% A MHUTAfiHHUr O LWHHHHT L L 7 )D 3? 5 fi fiu M. M L i a l w FIG.I

FIG.2

FIG.4

INVENTCRS FRANK J. HOHL BY CARL J. MILAZZO FIG.5

ATTORNEYS ACCUMULATING CONVEYOR BACKGROUND OF THE INVENTION Thisinvention relates generally-to the conveyor art and, more particularly,to a new and useful accumulating and transfer conveyor of the liveroller type.

Conventional accumulating conveyors of the live roller type are oftendriven by an endless belt maintained in frictional engagement witheither the under surfaces or the upper surfaces of the rollers.Sometimes, an improperly oriented load or a load pile-up occurssomewhere along the conveyor upstream of the accumulating area and thenormal frictional force of the drive belt against the-rollers isntsufficient to overcome the static or stationary load on the rollers andthe latter slip relative to the stationary load. In an effort toinitiate movement of a stationary load without unduly increasing thehold-back force for accumulation in those arrangements where the endlessbelt engages the under surfaces of the rollers, a pad is sometimes usedin conjunction with the belt. However, the pad moves in a directionopposite that of the conveyed article whereby the load is only indexed ashort distance commensurate with the length of the pad.

In those known arrangements where the belt engages the upper surfaces ofthe rollers, the belt is located at one side of the conveyor and isrelatively narrow to allow room for the loads to be conveyed, thuslimiting the drive capacity of the belt. Accordingly, weights or othermeans sometimes are employed to press the belt against the rollers toincrease the frictional engagement therebetween to maintain movement ofthe conveyed articles and to initiate movement of static loads. Thesearrangements have the disadvantage that a constant friction force isproduced along the length of the conveyor, requiring a relatively largehold-back force for accumulation with the resulting possibility ofdamage to the products being accumulated and an increase in belt drivingrequirements. Moreover, the superstructure associated with the drivebelt impedes accessto the conveyor from that side.

SUMMARY OF THE INVENTION A primary object of the present invention is toprovide' an accumulating conveyor of the belt-driven, live roller typewhich obviates the above disadvantages and which requires only a minimumof hold-back force for accumulation of the product being conveyed.

The apparatus of the presentinvention, as hereinafter described,obviates the prior art disadvantages by providing an accumulatingconveyor having live rollers with reduced diameter portions centrallythereof for receiving an endless drive member of sufficient width andweight frictionally engagable with such reduced diameter portionsnormally to maintain the forward motion of the product being conveyed,and which includes means on the drive member for engagement with astationary load to initiate movement of the latter along the conveyor.

The drive belt is of a thickness less than the depth of such grooves,and can be of very substantial width without interfering with theconveying area of the conveyor. Thus, more space is available on therollers for conveying loads and both sides of the conveyor areaccessible for the placement of loads on or the removal thereof from theconveyor.

Various other novel features of construction and advantages provided bythe conveyor construction of the present invention are pointed out inthe following detailed description of an illustrative embodiment thereofconsidered in conjunction with the accompanying drawing depicting thesame wherein like numerals represent like parts throughout the variousviews.

BRIEF DESCRIPTION OF THE DRAWING FIGURES FIG. 1 is a top plan view of anaccumulating transfer conveyor of the present invention with partsbroken away for ease of illustration;

FIG. 2 is a side elevational view of the conveyor shown in FIG. 1;

FIG. 3 is a fragmentary sectional view, on an enlarged scale, takenabout on line33 of FIG. 1, showing one form of pad used in conjunctionwith the drive belt;

FIG. 4 is a view similar to FIG. 3, showing another form of pad used inconjunction with the drive belt; and

FIG. 5 is a vertical sectional view, on an enlarged scale, taken abouton line 55 of FIG. 1.

DETAILED DESCRIPTION OF AN ILLUSTRATIVE EMBODIMENT Referring now indetail to the drawing, there is shown in FIGS. 1 and 2 an illustrativeaccumulating transfer conveyor of this invention comprising a supportingframe; generally designated 10, having opposite side rails 12 ofgenerally channel shaped cross section. End frame members 14 and 16 aresecured to opposite ends of side rails 12 and are supported by legs 18.A suitable drive motor 22, mounted on frame 10, is connected to a drivepulley 24 by means of a chain drive 26. Drive pulley 24 is drivinglyconnected to a drive roller25 suitably journalled for rotation in endframe members 16 and an idler roller 28 is journalled for rotation inthe opposite end frame member 14.

A series of article supporting live rollers 30 are provided, having stubshafts 32 at opposite ends thereof suitably journalled for rotation inside rails 12. Rollers 30 are provided with conventional ball bearing orlike supports, the details of which are not essential to this inventionand therefore are not illustrated, it being understood that the rollersare journalled with a minimum of friction.

In accord with this invention, each roller 30 is provided with a.central, reduced diameter portion 34 (FIG. 5) forming a peripheralchannel for receiving and guiding a drive belt 36 therein. Drive belt 36constitutes the drive for rollers 30 and is trained about roller 25 andidler roller 28, which also have central reduced diameter portions, formovement in an endless, orbital path. Belt 36 is supported on its returnrun by rollers 38 having stub shafts 40 at their opposite ends suitablyjournalled for rotation in brackets 42 secured to the bottom of frameside rails 12.

Drive belt 36 extends along the upper surfaces of the reduced diameterportions 34 of rollers 30, as shown in FIGS. 1 and 5, and presents tothese portions 34 a friction surface having a relatively highcoefficient of friction sufficient to maintain rotation of rollers 30 toconvey articles disposed thereon under normal operating conditions. Thethickness of drive belt 36is slightly less than the radial depth of thechannel defined by the reduced diameter portion 34 of each roller 30 toprevent engagement or contact of drive belt 36 with the articles beingconveyed. Endless drive belt 36 is formed of any suitable material, suchas woven cotton for example and can be provided with a poly vinyl orother friction coating on the roller engaging side of the belt, ifdesired, to increase the coefficient of friction thereof and increaseits roller rotating ability. However, the friction force applied torollers 30 by belt 36 preferably is of a magnitude less than thatnormally required to overcome the inertia of a static load disposed onrollers 30 and initiate rotation thereof or to convey loads underabnormal conditions, such as loads which might be oriented askew to therollers or where a pileup occurs. The weight of belt 36 and theresulting friction force on rollers 30 is selected so as to besufficient normally to maintain rotation of rollers 30 and forwardmotion of the articles being conveyed but generally insufficient toovercome the inertia of static loads on the rollers to initiate rotationof the latter. As a result, only a minimum of hold-back force isrequired for product accumulation and the power requirements necessaryto maintain rotation of rollers 30 under normal operating conditions iskept to a minimum.

A particular feature of the present invention is the provision of meanscarried by drive belt 36 for engaging and conveying static loads orunusually heavy and abnormal loads and stationary loads which are stuckfor any reason, without however unduly increasing the hold-back forcerequired for accumulation. Such means comprises two or more pads 46secured to drive belt 36 on the side opposite the roller engagingfriction surface and equally spaced apart on belt 36. As shown in FIG.3, each pad 46 projects above the peripheral surfaces of the largerdiameter, article engaging portions of rollers 30, on opposite sides ofbelt 36, and is adapted to engage behind stationary article or load Lsupported on rollers 30 and initiate and maintain forward movementthereof. However, if the load is accumulating and held against forwardmovement by suitable stop means (not shown) at the left end of theconveyor, pad 46 is so designed as to pass beneath the load, elevatingit slightly as the pad 46 passes therebeneath. To this end, pads 46 havea low silhouette and project only slightly above the article engagingsurfaces of rollers 30, for example on the order of one-eighth toonefourth inch.

Pads 46 can be made of the same material as belt 36, such as wovencotton for example, and formed integral therewith or adhesively orotherwise fixedly secured to drive belt'36. In order to enable pads 46to more readily slide beneath an accumulating load at the end of theconveyor, the upper or load engaging surfaces of pads 46 can be providedwith a thin layer of an anti-friction material, such as teflon or nylonfor example. However, it should be understood that pads 46 are intendedto pass beneath accumulating loads only in the accumulating area andthat pile-ups or static loads upstream of the accumulating area will beengaged by pads 46 and normally moved forwardly thereby.

Pads 46 are of a thickness causing them to project only slightly abovethe belt receiving grooves of rollers 30. The leading edges 48 of pads46 can be sloped or otherwise shaped to slide easily beneath anaccumulating load. Also, the width and lengths of pads 46 can vary, asdesired.

FIG. 4 illustrates another form of pad 50 which can be separatelyfabricated and formed of a different material, such as woven steel forexample. Pad 50 serves as a splice secured at its opposite ends to belt36 and like pad 46 projects only slightly above the article engagingportions of rollers 30, so as to function in the same manner as pad 36.The article engaging upper surface of pad 50 also can be provided with alayer of anti-friction material, is desired.

In operation, endless drive belt 36 is driven in an irregular orbitalpath in the direction indicated by arrows A, by means of the drive motor22, chain drive 26 and drive pulley 24 and is guided over rollers 30centrally thereof in the channels defined by the reduced diameterportions 34 thereof. Belt 36 engages the upper surfaces of portions 34to maintain them rotating under normal conditions, the frictionalengagement of belt 36 against these reduced diameter portions 34 beingsufficiently normally to maintain forward motion of articles beingconveyed. The articles will be carried continuously along the entirelength of the conveyor, the drive force imparted by belt 36 beingadequate to accomplish this with normal loads. The load can be removedat the left end of the conveyor or can be accumulated by providing stopmeans (not shown) on the left end of the conveyor. Once rollers 30 arerotating, the weight and frictional force of drive belt 36 on portions34 of rollers 30 is sufficient to continue to drive rollers 30 andconvey the load carried thereby under normal operating conditions. Inthe event of a load pile-up or accumulation somewhere along the conveyoror if a load is stuck or improperly placed on the conveyor, drive belt36 normally would not be effective to impart sufficient force toportions 34'of rollers 30 to maintain the latter rotating. However, thissituation is obviated as soon as the leading edge 48 of pad 46 engagesthe trailing edge of the stationary load to move the same forwardlyalong with belt 36.

Thus, it is seen that the present invention provides a novel and simpleaccumulating transfer conveyor for advancing loads in an efficientmanner requiring only a minimum hold-back force for accumulation. By theprovision of live rollers having reduced diameter portions to receiveand guide the drive belt, the full width of the conveyor is availablefor conveying articles. Also, a wider belt can be used to increase thefrictional contact area with the rollers and increase the drive capacitywhereby loads of up to fifty pounds can be conveyed by the live rollersof this invention. Where unusually heavy loads are encountered or wherethere is a load pile-up or improperly placed load somewhere along theconveyor upstream of the accumulating area, spaced pads secured to thebackside of the endless drive belt and projecting slightly above thearticle conveying surfaces of the rollers are operative to engage thetrailing edge of such stationary load to initiate forward movementthereof. Where the load is intended to be accumulated by stop means, thepads pass beneath the accumulated load, elevating it slightly as thepads pass thereby avoiding product damage during accumulation.

The foregoing detailed description is given by way of illustration only.

We claim:

1. A conveyor comprising: a supporting frame; a series of articleconveying live rollers joumalled on said frame; an endless drive member;said rollers having reduced diameter portions between the opposite endsthereof forming grooves for receiving and guiding said drive member;said drive member having one side in frictional contact with saidreduced diameter portions of said rollers; the frictional contactbetween said drive member and said rollers being sufficient normally tomaintain forward motion of articles being conveyed by generallyinsufficient to overcome the inertia of static loads on said rollers;and pad means carried by said drive member and projecting above thearticle engaging surfaces of said rollers, said pad means having aleading sloping edge surface for engagement with the trailing edge of astatic load to initiate forward motion thereof and a load contactingsurface extending from said leading edge surface and disposed so as topass beneath and elevate slightly a load which is accumulating andpositively held against forward movement.

2. A conveyor according to claim 1 wherein said endless drive member hasa thickness less than the depth of said grooves whereby the other sideof said drive member normally is spaced below the bottom of the loadbeing conveyed.

3. A conveyor according to claim 1 wherein said pad means is formed ofwoven metal spliced to said drive member.

4. A conveyor according to claim 1 wherein said pad means is formed ofthe same material as said drive member.

5. A conveyor according to claim 1 wherein a plurality of said pad meansare carried by said endless drive member in substantially equally spacedapart relation therealong.

6. A conveyor according to claim 1, wherein said belt receiving groovesare generally centrally located in said rollers.

7. A conveyor according to claim 1, further includinganti-frictionmaterial on said load contacting surface of said pad means.

UNITED STATES PATENT OFFICE I CERTIFICATE OF CORRECT-LON Patent No. 3,791, 510 Dated February 12, 1974 Inventor(s) Carl J. Milazzo, Frank J.Hohl I It is certified that error appearsv in the above-identifiedpatent and that said Letters Patent are hereby corrected as shown"below:

Claim 1, column 5; lirie 5 "by" should be changed to --but-- Signed andsealed this 17th day of September 1974.

(SEAL) Attest:

MCCOY M. GIBSON JR. I C. MARSHALL DANN Attesting Officer Commissioner ofPatents USCOMM-DC scan-P59 :2 us eovckrmsn-r rmmme ornca: was o-ass-a;4,

ORM PO-105O (IO-69)

1. A conveyor comprising: a supporting frame; a series of articleconveying live rollers journalled on said frame; an endless drivemember; said rollers having reduced diameter portions between theopposite ends thereof forming grooves for receiving and guiding saiddrive member; said drive member having one side in frictional contactwith said reduced diameter portions of said rollers; the frictionalcontact between said drive member and said rollers being sufficientnormally to maintain forward motion of articles being conveyed bygenerally insufficient to overcome the inertia of static loads on saidrollers; and pad means carried by said drive member and projecting abovethe article engaging surfaces of said rollers, said pad means having aleading sloping edge surface for engagement with the trailing edge of astatic load to initiate forward motion thereof and a load contactingsurface extending from said leading edge surface and disposed so as topass beneath and elevate slightly a load which is accumulating andpositively held against forward movement.
 2. A conveyor according toclaim 1 wherein said endless drive member has a thickness less than thedepth of said grooves whereby the other side of said drive membernormally is spaced below the bottom of the load being conveyed.
 3. Aconveyor according to claim 1 wherein said pad means is formed of wovenmetal spliced to said drive member.
 4. A conveyor according to claim 1wherein said pad means is formed of the same material as said drivemember.
 5. A conveyor according to claim 1 wherein a plurality of saidpad means are carried by said endless drive member in substantiallyequally spaced apart relation therealong.
 6. A conveyor according toclaim 1, wherein said belt receiving grooves are generally centrAllylocated in said rollers.
 7. A conveyor according to claim 1, furtherincluding anti-friction material on said load contacting surface of saidpad means.